CO2 Concrete Mineralization, USA

Concrete is the most widely used man-made material in existence. The single largest ingredient in concrete is cement, and it has a massive carbon footprint. If the cement industry were a country, it would be the third largest emitter in the world behind China and the US.

This project makes use of nascent stage technology that will capture CO2 that would have otherwise been emitted into the atmosphere and inject it into concrete as it is produced, thus mineralizing the CO2 in concrete. Carbon emissions are reduced and sequestered through this form of carbon capture and storage.

This innovative industrial process has the additional benefit of requiring less cement to create concrete. Globally, cement is the source of about 8% of the world’s carbon emissions meaning every reduction of emissions from this sector is meaningful. Around 98% of the credits from this project are reductions, and the remaining 2% are removals.

What is concrete mineralization?

Carbon mineralization in concrete is a method of carbon capture, utilization, and storage (CCUS) that involves injecting CO2 into fresh concrete during the mixing process. This technique offers several benefits for decarbonizing the concrete industry:

• Permanent CO2 sequestration: The injected CO2 reacts with calcium oxide in the cement, forming nano-calcium carbonate (CaCO3) minerals that become permanently embedded in the concrete. This process can sequester carbon for hundreds of thousands of years, as the CO2 becomes part of the crystal structure of the minerals.
• Improved concrete properties: Carbon mineralization can enhance concrete's strength and durability while reducing its carbon footprint. It can also accelerate the curing process, making it faster than the conventional 28-day curing period.
• Cost-effective solution: The technology can be implemented with a simple, low-cost retrofit to existing concrete production facilities, making it an accessible option for reducing emissions in the construction industry. Carbon mineralization can be applied across various concrete manufacturing processes, including ready-mix, precast, and recycled concrete aggregate.

Carbon mineralization in concrete represents a promising approach to reducing the carbon footprint of the construction industry while creating a valuable, marketable product that permanently stores CO2.

In addition to delivering emission reductions over the project’s lifetime to take climate action (SDG 13), the project delivers additional benefits:

• Clean Water Use and Sanitization: Increases change in water-use efficiency over time
• Decent Work and Economic Growth: Decreases unemployment rate, by sex, age and persons with disabilities
• Industry Innovation and Infrastructure: Decreases CO2 emission per unit of value added
• Sustainable Cities and Communities: Increases proportion of financial support to the least developed countries that is allocated to the construction and retrofitting of sustainable, resilient and resource-efficient buildings utilizing local materials
• Responsible Consumption and Production: Decreases material footprint, material footprint per capita, and material footprint per GDP as well as domestic material consumption, domestic material consumption per capita, and domestic material consumption per GDP
• Climate Action: Decreases total greenhouse gas emissions per year